So, my Dart has been having a wide variety of fuel problems in my opinion and I think I'm getting to the root cause. I just want to make sure I'm going along the right path. The car has a 408ci engine, stock fuel tank, holley blue electric fuel pump that feeds into a pressure regulator, and a holley 850 dp carb.
Here are a couple of my problems. Depending on how the car feels that day will depend on whether or not it wants to start up. On some days, I can start it up on the first or second try (second try because I'm still learning it). These are usually colder mornings (40-60F). Other times, I have to try 3-5 times. I'll turn the key to prime the pump, wait awhile, put my foot on a little past half throttle and turn the key letting my foot off the gas. 75% of the time, the car will run for about 5 seconds and then die out. Half the time when I give the throttle just a little tap after it starts up it will shut off and the other half it will start singing a new tune and then properly warm up. The car does not like to run until water temp reaches about 150F. My other problem was that the car got about 6.7 mpg. Granted, I did drive it 80% of the time on the streets and having fun, but that seems a little low for a car that has a T56 and no autocrossing, yet. Lastly, at my last autocross, during 2 of my 4 runs, on the first corner the car would die out. Now this corner was tight, slightly uphill off camberish, and not very high speeds. But this caused me to DNF and that's no fun. After the car died out, it took another minute of multiple attempts to start the car. Pretty embarrassing.
So, first off, the car was smelling of fuel pretty bad around the gas cap. I took a look at the gas cap and sure enough, the gasket had cracks along the end and some evidence of drizzling fuel. So, I bought a new locking gas cap which may help with my fuel mileage issue as this gasket has a much larger gasket. Plus now I have added security with the locking feature. In the past day or two, the car doesn't smell like fuel anymore; however, I won't have an opportunity to drive it till tomorrow to see if it will leak.
Second, I've been watching videos on how to tune a Holley Carb on Youtube. It's been super helpful and here are two things I think I may have to adjust; however, I feel that one may fix the problem. A common theme in these videos is that the Holley carb generally likes to run at about 6psi of fuel pressure at idle and that 7psi is it's max and it doesn't like it there. I turned on my key and checked my gauge, prior to letting my car run. For the first 30 seconds the gauge reads 7 psi, the next 30 seconds it climbs to 8 psi, after that it drops down and flickers back and forth between 6.5-7 psi. So, my guess is I need to tune the regulator down so that the carb is getting 6psi of fuel pressure and my backup option would be adjusting the floats.
I know that was long, but do you guys think I'm on the right path?
Here are a couple of my problems. Depending on how the car feels that day will depend on whether or not it wants to start up. On some days, I can start it up on the first or second try (second try because I'm still learning it). These are usually colder mornings (40-60F). Other times, I have to try 3-5 times. I'll turn the key to prime the pump, wait awhile, put my foot on a little past half throttle and turn the key letting my foot off the gas. 75% of the time, the car will run for about 5 seconds and then die out. Half the time when I give the throttle just a little tap after it starts up it will shut off and the other half it will start singing a new tune and then properly warm up. The car does not like to run until water temp reaches about 150F. My other problem was that the car got about 6.7 mpg. Granted, I did drive it 80% of the time on the streets and having fun, but that seems a little low for a car that has a T56 and no autocrossing, yet. Lastly, at my last autocross, during 2 of my 4 runs, on the first corner the car would die out. Now this corner was tight, slightly uphill off camberish, and not very high speeds. But this caused me to DNF and that's no fun. After the car died out, it took another minute of multiple attempts to start the car. Pretty embarrassing.
So, first off, the car was smelling of fuel pretty bad around the gas cap. I took a look at the gas cap and sure enough, the gasket had cracks along the end and some evidence of drizzling fuel. So, I bought a new locking gas cap which may help with my fuel mileage issue as this gasket has a much larger gasket. Plus now I have added security with the locking feature. In the past day or two, the car doesn't smell like fuel anymore; however, I won't have an opportunity to drive it till tomorrow to see if it will leak.
Second, I've been watching videos on how to tune a Holley Carb on Youtube. It's been super helpful and here are two things I think I may have to adjust; however, I feel that one may fix the problem. A common theme in these videos is that the Holley carb generally likes to run at about 6psi of fuel pressure at idle and that 7psi is it's max and it doesn't like it there. I turned on my key and checked my gauge, prior to letting my car run. For the first 30 seconds the gauge reads 7 psi, the next 30 seconds it climbs to 8 psi, after that it drops down and flickers back and forth between 6.5-7 psi. So, my guess is I need to tune the regulator down so that the carb is getting 6psi of fuel pressure and my backup option would be adjusting the floats.
I know that was long, but do you guys think I'm on the right path?